Merge pull request #2651 from dsander/upgrade-rack

Upgrade rack to 2.0.8 to fix CVE

Gemfile.lock

@@ -474,7 +474,7 @@ GEM
     pry-rails (0.3.4)
       pry (>= 0.9.10)
     public_suffix (3.0.2)
-    rack (2.0.6)
+    rack (2.0.8)
     rack-livereload (0.3.16)
       rack
     rack-test (1.1.0)